The invention relates to a mechanism for easy and quick adjustment of optical components with two degrees of freedom, applicable with advantage to course and fine, invariant setting of optical components, such as mirrors and lenses, around two axes perpendicular to each other.
As is known, it is a general task in accomplishing optical setups and optical trains to adjust mirrors and lenses in relation to the path of rays with specified precision. A limit is imposed on the attainable precision of setting by the stickslip resulting from the sliding or rolling friction between elements of the setting mechanism while being displaced with respect to each other. A general requirement to be fulfilled by the setting mechanisms is to minimize the errors due to the effects of stick slip arising in the course of adjustments. This is especially important with the spreading use of laser applications, where precision of setting has be equal to, or better than the wavelength of light, i.e. the precision should fall into the interferometric range of accuracy.
In Hungarian patent specification No. 177670, a swing mounting suitable for the adjustment of optical elements to interferometric precision with two degrees of freedom and for the centering of such elements is described.
In the specification it is stated that by means of the bearing arrangement accomplishing conditions of pure rolling friction, the stick slip occuring in the course of adjustments has been considerably reduced, but not entirely eliminated. The effect causing the phenomenon of stick slip and resulting from differing magnitudes of static and moving frictions cannot fully be eliminated by applying rolling guide elements.
Another deficiency of the described mechanism can be attributed to the centering insert built up of many kinematic pairs that fail to fulfil the severe requirements of mechanical stability indispensable with adjustments of interferometric precision.
A great disadvantage of the prior mechanism lies in its relatively narrow setting range and in the limited accuracy and reproducibility of settings, rendering it unsuitable for making adjustments equal to, or better than, the wave lengths of light.
A further drawback of the mechanism is that on the course of high-precision interferometric measurements, adjustments can only be made very slowly.
The purpose of the present invention is to eliminate simultaneously all of the above deficiencies by providing a mechanism suitable for rapid and invariant stick-slip free adjustment of the angular position of optical elements with two degrees of freedom and with a precision equal to, or better than the wave lengths of light, and by being relatively simple in its construction permitting economical production.